When constructing an empty QString in Qt, which way is the most efficient?

When constructing an empty QString in Qt,

• QString()
• QString("")
• QLatin1String()
• QLatin1String("")
• QLatin1StringView()
• QLatin1StringView("")
• QStringLiteral()
• QStringLiteral("")

Which one is the most efficient?

QString has "null" state, meaning there is no allocation for string data. You get a QString like this with default constructor. More "modern" way than QString() is QString{}.

Short syntax is {}, if compiler can deduce the type. For example return {}; is an idiomatic way to return default-constructed value from function, without needing to repeat the type.

Initializing with any string will do varying amounts of additional allocation, initilaization, encoding conversion.